Myeloid-derived suppressor cells (MDSC) play a crucial role in inhibiting anticancer defenses, resulting in tumor escape from immunologic surveillance, progressive cancer growth and metastasis. MDSC are a heterogeneous group of leucocytes present in the circulation, lymphoid compartments and infiltrating human cancers inhibiting cell-mediated immune functions1. Immunotherapeutic strategies capable of inhibiting or deleting MDSC are desirable to enhance antitumor immune response.
MDSC have recently been shown to be involved in chronic viral illnesses2,3. Several chronic viral infections such as chronic viral hepatitis C, are known to respond to interferon, but again, such response in these patients is not universal even within a specific genotype and predictors of clinical response in these patients are necessary.
Interferons (IFN) are common therapies used for various medical conditions, including melanoma, lymphoma, hepatitis and many others. However, currently, there are no specific biomarkers to distinguish which patient population would respond to the therapy with IFN. As a result, all patients receive this toxic therapy on a trial-and-error basis without knowing a priori whether they would benefit from it or not.
According to a comprehensive report “Interferon Market Forecast to 2015” dated Nov. 2, 2012 (marketandreports.wordpress.com), the consumption of the interferon drugs is increasing, and is expected to cross the $10 billion-mark by 2015. Increasingly, in light of shrinking healthcare dollars, insurance companies begin to demand significant supporting evidence for inclusion of drugs into formularies and verification of their cost-effectiveness. In the future, therapeutic choices will be limited even more by these restrains. It would be of great benefit to have a standard test predictive of a response to IFN, to increase cost-benefit ratio and to provide valuable therapy to those who would benefit from it the most, while sparing others from undesirable toxicity and unnecessary financial losses.